Search

CN-122015337-A - Determination method of temperature of fin coil pipe and heat pump system

CN122015337ACN 122015337 ACN122015337 ACN 122015337ACN-122015337-A

Abstract

The application relates to a method for determining the temperature of a fin coil and a heat pump system, wherein the method is characterized in that whether the absolute temperature difference between the temperature of a bottom coil and the temperature of a middle coil of a fin heat exchanger is within a set temperature difference threshold value range is compared, the running mode of the heat pump system and corresponding control logic are combined, the temperature of the bottom coil or the temperature of the middle coil or the average value of the temperature of the two is selected as a control parameter for controlling the refrigerant flow of the heat pump system according to different functional scenes, and the accuracy of controlling the refrigerant flow and the rotating speed of a fan based on the temperature of the coils can be effectively improved by the double-coil temperature control scheme, so that the functions of hot water control, refrigeration control, defrosting control, superheat degree control, fan control, over-high temperature protection of the refrigeration coil and the like of the heat pump system are more accurate and timely, the running stability and reliability of the heat pump system are obviously improved, and the adaptability of the heat pump system under complex working conditions is enhanced.

Inventors

  • WU JINGLONG
  • TONG FENGXI

Assignees

  • 中山市爱美泰电器有限公司
  • 热立方科技(佛山市)有限公司

Dates

Publication Date
20260512
Application Date
20260128

Claims (10)

  1. 1. The method for determining the temperature of the fin coil is suitable for a heat pump system with a first temperature sensor arranged at the bottom coil and a second temperature sensor arranged at the middle coil of the fin heat exchanger, and is characterized by comprising the following steps of: S10, acquiring a control logic corresponding to an operation mode and a current operation mode of a heat pump system; S20, obtaining the bottom temperature of the coil And the temperature of the middle part of the coil pipe ; S40, calculating the bottom temperature of the coil With the temperature in the middle of the coil pipe Determining whether the absolute difference DeltaTp is equal to or greater than an absolute difference threshold DeltaTp : If yes, go to step S50A; if not, executing step S50B; S50A, in the control logic of the exhaust superheat degree in the refrigeration mode, the method As a temperature control coil The rest of the cases will As a temperature control coil ; S50B, in the wind speed control logic or fin over-temperature protection logic of the refrigeration mode, the method As a temperature control coil In the hot water mode, the air speed control logic or the fin temperature control logic in the defrosting mode As a temperature control coil The rest of the cases will As a temperature control coil ; Wherein, the Indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is the maximum value of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is the minimum of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is a mean value of (c).
  2. 2. The method of determining a temperature of a fin coil according to claim 1, wherein the temperature of the control coil is determined by As the evaporation temperature T E , S60A is also included: When the hot water mode is operated, the ambient temperature Ta is obtained, the coil temperature compensation value DeltaT R is determined according to the temperature interval to which the ambient temperature Ta belongs, and the temperature of the control coil is controlled according to the coil temperature compensation value DeltaT R The evaporation temperature T E was calculated.
  3. 3. The method of determining a temperature of a finned coil according to claim 2, wherein a first ambient temperature threshold is employed Second ambient temperature threshold Dividing the temperature interval into three temperature intervals, corresponding to three different side coil temperature compensation values, and calculating the evaporating temperature T E as follows: If the ambient temperature Ta is greater than or equal to the first ambient temperature threshold value Coil temperature compensation value Δt R = Evaporation temperature T E = + ; If the ambient temperature Ta is less than or equal to the second ambient temperature threshold value Coil temperature compensation value Δt R = Evaporation temperature T E = + ; If the second ambient temperature threshold value < Ambient temperature Ta < first ambient temperature threshold value Coil temperature compensation value Δt R = Evaporation temperature T E = + ; Wherein, the For the first coil temperature compensation value, Is the temperature compensation value of the second coil pipe, The temperature compensation value of the first coil is the temperature compensation value of the third coil Second coil temperature Compensation value Second ambient temperature threshold < First ambient temperature threshold 。
  4. 4. The method of claim 3, wherein the third coil temperature compensation value The method meets the following conditions: 。
  5. 5. The method of determining a temperature of a fin coil according to claim 1, wherein the temperature of the control coil is determined by As the condensation temperature T C , S60B is also included: When the refrigerating mode or the defrosting mode is operated, a coil temperature compensation value DeltaT R is obtained; Based on the coil temperature compensation value DeltaT R , the temperature of the coil for control The condensation temperature T C is calculated: T C = +△T R , wherein Δt R is a set constant C.
  6. 6. The method of determining the temperature of a finned coil according to claim 1, further comprising step S30: According to the operation mode and the temperature of the bottom of the coil pipe And the temperature of the middle part of the coil pipe Judging whether the first temperature sensor and the second temperature sensor have faults or not: if the first temperature sensor and the second temperature sensor are normal, executing step S40; If the first temperature sensor and the second temperature sensor are abnormal, an alarm is given out and the machine is stopped; if the first temperature sensor or the second temperature sensor is normal, one of them is used.
  7. 7. The method of claim 6, wherein the determination of the temperature of the bottom of the coil is performed in a hot water mode And the temperature of the middle part of the coil pipe Whether or not to [ + 1, 2] Range: if none is in [ + 1, 2] Within the range, judging that the first temperature sensor and the second temperature sensor are out of order, and alarming and stopping; If only the temperature of the bottom of the coil is In [ + 1, 2] If the first temperature sensor is judged to be normal, the evaporation temperature and condensation temperature calculation unit 36 is entered, and step S60 is executed; If only the temperature of the middle part of the coil pipe is In [ + 1, 2] If the second temperature sensor is judged to be normal, the evaporation temperature and condensation temperature calculation unit 36 is entered, and step S60 is executed; If all are in [ + 1, 2] And entering a coil temperature abnormality judging unit 34 to execute step S40; Wherein, the 2> 1; In the refrigeration mode, the temperature of the bottom of the coil pipe is judged And the temperature of the middle part of the coil pipe Whether or not to [ , In the range: if none is in [ , If the temperature is within the range, judging that the first temperature sensor and the second temperature sensor are out of order, and alarming and stopping; If only the temperature of the bottom of the coil is In [ , If the first temperature sensor is judged to be normal, the evaporation temperature and condensation temperature calculation unit 36 is entered, and step S60 is executed; If only the temperature of the middle part of the coil pipe is In [ , If the temperature is within the range, the second temperature sensor is judged to be normal, and the evaporation temperature and condensation temperature calculation unit 36 is entered to execute the step S60; If all are in [ , If the temperature range is within the range, the coil temperature abnormality judging unit 34 is entered, and the step S40 is executed; Wherein, the > 。
  8. 8. The heat pump system comprises a compressor, a reversing four-way valve, a water side heat exchanger, a throttling component, a fin heat exchanger and a fan arranged on one side of the fin heat exchanger, wherein the compressor, the reversing four-way valve, the water side heat exchanger, the throttling component and the fin heat exchanger are circularly connected through a refrigerant pipeline; the working condition acquisition unit is used for acquiring an operation mode of the heat pump system and control logic corresponding to the current operation mode; the coil temperature acquisition unit is used for acquiring the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe ; The coil temperature abnormality judging unit is used for calculating the temperature of the bottom of the coil With the temperature in the middle of the coil pipe Determining whether the absolute difference DeltaTp is equal to or greater than an absolute difference threshold DeltaTp : If yes, entering a first coil temperature determining unit; if not, entering a second coil temperature determining unit; The first coil temperature determining unit is used for controlling the superheat degree of exhaust gas in a refrigerating mode As a temperature control coil The rest of the cases will As a temperature control coil ; The second coil temperature determining unit is used for controlling the air speed in a refrigerating mode or protecting the fin from over-high temperature As a temperature control coil In the hot water mode, the air speed control logic or the fin temperature control logic in the defrosting mode As a temperature control coil The rest of the cases will As a temperature control coil ; Wherein, the Indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is the maximum value of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is the minimum of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipe Is a mean value of (c).
  9. 9. The heat pump system according to claim 8, further comprising a temperature sensor for detecting an ambient temperature, wherein the controller further comprises an evaporation temperature calculation unit for acquiring the ambient temperature Ta when the hot water mode is operated, determining a coil temperature compensation value Δt R according to a temperature interval to which the ambient temperature Ta belongs, and controlling a coil temperature according to the coil temperature compensation value Δt R The evaporation temperature T E was calculated.
  10. 10. The heat pump system of claim 8 or 9, wherein the controller further comprises a condensing temperature calculation unit for obtaining a coil temperature compensation value DeltaT R when the cooling mode or the defrosting mode is operated, and controlling the coil temperature according to the coil temperature compensation value DeltaT R The condensation temperature T C is calculated.

Description

Determination method of temperature of fin coil pipe and heat pump system Technical Field The invention relates to the technical field of heat pump system control, in particular to a method for determining the temperature of a fin coil pipe and a heat pump system. Background The existing heat pump system generally consists of a compressor, a water side heat exchanger, an electronic expansion valve, a fin heat exchanger and a controller. The controller controls the system to operate by collecting temperature and pressure information, wherein the temperature of the fin coil is used as an important parameter for the operation of the heat pump system, and the temperature of the fin coil is related to defrosting function, superheat control, fan control, over-temperature protection of the refrigerating coil and the like. Therefore, ensuring the accuracy of fin temperature detection is critical to the stable operation of the heat pump system. Currently, heat pump systems fix a single temperature sensor on the coil of the bottom flow path of the fin heat exchanger to detect the fin coil temperature. This method of providing a single temperature sensor to obtain the temperature of the finned coil has the following drawbacks: 1) The temperature of the coil pipe detected by the single temperature sensor has deviation from the actual condensing temperature or evaporating temperature, and particularly under a refrigerating or heating mode, the temperature of the coil pipe of the bottom flow path cannot accurately represent the temperature of the whole coil pipe, so that the control function is inaccurate; 2) When the sensor is fixed at the position of the coil pipe, the problem of poor heat preservation or falling easily occurs, and the stability of the system is affected; 3) When the fin heat exchanger is uneven in flow distribution, the data deviation of a single detection point is larger, and the reliability of system control is further reduced. These problems make the heat pump system perform poorly in key functions such as defrosting and superheat adjustment. Disclosure of Invention Based on the above, the invention aims to provide a method for determining the temperature of a fin coil and a heat pump system, which can obtain stable and reliable temperature of the fin coil, so that deviation between the detected temperature of the fin coil and the actual evaporation temperature or condensation temperature is smaller, and stable operation of the heat pump system is ensured. A method for determining the temperature of a fin coil is suitable for a heat pump system with a first temperature sensor arranged at the bottom coil and a second temperature sensor arranged at the middle coil of a fin heat exchanger, and comprises the following steps: S10, acquiring a control logic corresponding to an operation mode and a current operation mode of a heat pump system; S20, obtaining the bottom temperature of the coil And the temperature of the middle part of the coil pipe; S40, calculating the bottom temperature of the coilWith the temperature in the middle of the coil pipeDetermining whether the absolute difference DeltaTp is equal to or greater than an absolute difference threshold DeltaTp: If yes, go to step S50A; if not, executing step S50B; S50A, in the control logic of the exhaust superheat degree in the refrigeration mode, the method As a temperature control coilThe rest of the cases willAs a temperature control coil; S50B, in the wind speed control logic or fin over-temperature protection logic of the refrigeration mode, the methodAs a temperature control coilIn the hot water mode, the air speed control logic or the fin temperature control logic in the defrosting modeAs a temperature control coilThe rest of the cases willAs a temperature control coil; Wherein, the Indicating the temperature of the bottom of the coilAnd the temperature of the middle part of the coil pipeIs the maximum value of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipeIs the minimum of (2); indicating the temperature of the bottom of the coil And the temperature of the middle part of the coil pipeIs a mean value of (c). Further, the temperature of the coil pipe for control is controlledAs the evaporation temperature T E, S60A is also included: When the hot water mode is operated, the ambient temperature Ta is obtained, the coil temperature compensation value DeltaT R is determined according to the temperature interval to which the ambient temperature Ta belongs, and the temperature of the control coil is controlled according to the coil temperature compensation value DeltaT RThe evaporation temperature T E was calculated. Further, a first ambient temperature threshold is employedSecond ambient temperature thresholdDividing the temperature interval into three temperature intervals, corresponding to three different side coil temperature compensation values, and calculating the evaporating